COGNITIVE CONSTRAINTS ON THE EMERGENCE OF TOPIC-FOCUS STRUCTURE IN HUMAN COMMUNICATION

Human information processing is managed by a resource-limited system. For this reason, information in utterances must be packed in a way that prevents it from being lost in decoding. A developmental model of information structure units is proposed according to which Topic-Focus articulation has emerged in order to comply with this constraint. The basic function of Topic and Focus is to instruct the addressee to different attitudes: Focus causes controlled, more effortful processing; Topic automatic, less effortful processing. This model accounts for the well-known restriction on the iteration of Foci in sentences – because cognitive resources for multiple Foci are not available – but it also explains at which conditions can the expression of more new ideas in a single utterance happen with overall bearable costs for the speaker and receiver, thus increasing efficiency in communication.